This invention concerns an electromagnetic relay having a base plate through which a plurality of terminal tongues extend, with an armature mechanically attached to a switching contact spring being arranged thereon, and with a first portion of the contact spring supporting at least one switching contact.
Modern motor vehicles, which have a multiplicity of electronic apparatus, particularly employ, among other components, microrelays. In this regard, small-size, or small-structure, relays, so called microrelays, that only require small amounts of mounting space and therefore can be particularly easily integrated into complex electronic circuits, are increasingly preferred.
Naturally, a very good operation and life span is demanded when such microrelays are employed. At the same time, manufacturing costs of such relays should, of course, remain low. Therefore, the manufacture of microrelays presents the following problems:
For large structure relays generally, manufacturing procedures are preferred which can be carried out without adjustments of combined relay components, because adjustment process steps represent substantial costs.
Particularly small microrelays require, compared to large relays, an especially exact fabrication process. The individual relay components can therefore, as is required by their size, have only very small manufacturing tolerances, so that fabrication of microrelays is relatively expensive. Experience has shown that for manufacturing microrelays it is more expedient to allow larger manufacturing tolerances for individual relay components and, because of this, upon combining the components to perform adjustments, particularly adjustments of positions of components relative to one another.
This proves to be particularly cost-effective if adjustments can be made during assembly of the relay components.
In this regard, it is necessary that a fully assembled relay be designed so that it can be mounted, or fabricated, in a particularly uncomplicated and cost-effective manner and so that, preferably, during such mounting, uncomplicated, cost-effective and fully automatic adjustments, particularly of spaces, or clearances, of relay components relative to one another are possible.
A shape as well as a position of a switching contact spring is related to adjustment of sizes, and spaces, of such a relay. The arrangement of the switching contact spring influences namely, particularly, a minimum attraction voltage of a relay (that is, the smallest voltage with which the relay reliably pulls up, or activates).
For many uses, only a very small window of tolerance of the minimum attraction voltage is allowable. Particularly relays with minimum attraction voltages which are too high are rejected or must be reworked in a cost-intensive manner, often by hand. It is therefore practical for such an arrangement, that the shape and position of a switching contact spring, to be adjustable.
In this regard, German Offenlegungsschrift DE-OS 32 35 714 discloses a process and an apparatus involving a contact spring of an electromagnetic relay which can be adjusted. To do this, targeted, or intended, points on the respective contact spring can be illuminated, or energized, by a laser beam. Local warming can cause a desired bend, and thereby accomplish a desired adjustment of a contact spring.
This applied process as well as the apparatus suggested therefor is complicated and expensive. On the one hand, a functional interrelationship between an energized area and illumination time with a resulting bending of the contact spring must be known and, on the other hand, to carry out this process, it is necessary to have an apparatus for creating a laser beam, an electro-optical apparatus to guide the laser beam, a calculator to control the electro-optical apparatus as well as an optical-measuring arrangement to measure respective changing positions of the contact spring, with the optical measuring device also being coupled to the calculator.
It is also a disadvantage that adjustment of the contact spring thereby takes place in a separate process step after the relay is assembled.
Relays of the general type of this invention are disclosed in German Offenlegungsschriften DE-OS 27 05 961 and DE-OS 40 35 586. These publications describe armature-supporting switching contact springs having functions of return springs.
U.S. Pat. No. 3,239,630 describes a relay having a coupling element between an armature-supporting switching contact spring and a terminal stud which is constructed as a spring clamping connection. This construction of the coupling element is meant to particularly prevent soldering connections on the relay.
It is disadvantageous, in this regard, that such a spring clamping connection allows undue movement. Thus, a good and, above all, lasting adjustment of the relay is not guaranteed.
It is therefore an object of this invention to provide a relay that has an uncomplicated and cost-effective construction and with which a lasting adjustment of a switching contact spring can take place in a particularly uncomplicated and cost-effective manner and indeed during mounting, or assembly, of the relay.